Add tests for Section 3.2, 3.3 and 3.4 of RFC6321.
Add tests for Section 3.2, 3.3 and 3.4 of RFC6321.

Also format tests. Easier to read with some helpers.

fruux/sabre-vobject,sabre-io/vobject,linagora/sabre-vobject,armin-hackmann/sabre-vobject